Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates to coupling mechanisms, and more specifically to couplings for mechanical, hydraulic and electrical systems.
2. Description of the Related Art
Quick connect/disconnect mechanical couplings are connecting devices which permit easy, immediate connection and separation of fluid lines and electrical conductors. Typically, mechanical couplings are made up of two members commonly referred to as a male or pin connector and a female or socket connector.
Mechanical fluid couplings are typically designed to provide rapid coupling and uncoupling of high pressure lines while at the same time providing a high degree of safety during both flow and non-flow conditions. It is important that the fluid coupling assures positive locking and a fluid-tight joint in the high pressure line. The mechanical fluid couplings are generally designed to assist in overcoming the resistive forces of joining the coupling members resulting from the fluid pressure in the lines.
A common fluid coupling designed to assist in joining the coupling connectors is the threaded coupling having a threaded coupling nut which is captured by a shoulder and a retaining ring on a first coupling connector. A second coupling connector has an externally threaded portion. As the coupling nut is threaded on the externally threaded portion of the second coupling connector, the coupling nut acts against the shoulder of the first coupling connector drawing the coupling connectors together. The same principle is used with dogs or lugs to engage camming surfaces within a locking sleeve of a coupling connector. There is also the bayonet coupling whereby dogs or lugs fixed to one coupling connector react against a cam surface on the other coupling connector as one member is rotated relative to the other. One good feature of threaded couplings is that they are not likely to disconnect accidentally.
A non-threaded type coupling is a push style mechanical coupling which involves the displacement of a spring-loaded sleeve. The displacement of the spring-loaded sleeve allows locking members to move radially outward as the pin is inserted into the socket. Once the pin is fully engaged, the spring-loaded sleeve is released. As the spring-loaded sleeve returns to its normal position, an interior cam surface forces and holds the locking members in the pin""s groove, thereby locking the pin within the socket. Unlocking involves the reverse process. The locking members can be balls, pins, palls, wire rings, dogs, cams, collets, breech lugs, etc.
Electrical couplings do not encounter the high resistive forces of fluid couplings. However, electrical couplings must be sealed and polarized to ensure the proper coupling of the electrical conductors. Conventionally, electrical couplings achieve their polarization by an external-internal key and keyway usually in the proximity of the contacts. Sealing of the contact cavity is typically achieved by O-ring seal glands located in this same region. In order to achieve proper and timely key engagement and seal engagement without one interfering with the other, the coupling usually requires additional length of engagement and stepped diameters, thus increasing the complexity of the connector and thereby increasing manufacturing costs. The internal-external relationship of key and keyway results in one internal element being hidden from view while the other external element is obscured by the coupling ring. Inspection of the face of each connector will allow an approximate orientation of connectors prior to coupling, but indexing is strictly by feel upon engaging connectors, since the key and keyway are obscured. Obscure O-ring seal glands often result in failure of the coupling as a result of the seal glands not being properly in place or defective.
Threaded coupling arrangements are used extensively in mechanically coupled electrical connectors. The mechanical advantage as well as the relative unlimited travel make it a favorite in most applications over other types of couplings, such as lever or bayonet-type couplings. To perform as intended, it is necessary that the screw threads have proper maintenance such as protection, thread cleaning, and lubrication. The problems inherent with conventional threaded coupling arrangements are cross-threading and thread galling. Cross-threading may occur if the coupling members are not properly oriented and aligned when starting to engage the threads. Thread galling is the result of a contamination or burr being ground into the thread, creating a high stress or hot spot. This usually occurs on new parts being mated the first time. Conventional connectors are not necessarily sold as mated pairs and are therefore subject to being mated in the field for the first time. Additionally, a substantial reduction in efficiency and mechanical advantage results from resistance to thread make-up due to friction caused by corrosion, contamination, or improper lubrication. Conventional threaded couplers often are difficult to uncouple when the connectors have been made-up for an extended period of time in a hostile environment. Additionally, conventional connectors may suffer mashed, gouged, or bruised threads that may destroy the usefulness of the coupling connector.
Applicant""s U.S. Pat. No. 5,388,874 discloses a mechanical coupling including a plug assembly and a receptacle assembly with each having an interior coupling member. The plug assembly has a coupling nut rotatably connected to a first latching body. The coupling nut includes a threaded portion that is maintained in constant threaded engagement to a threaded portion of an inner body. The receptacle assembly has a second latching body adapted to interconnect with the first latching body. The first and second coupling members are coupled together by rotating the coupling nut and advancing the first coupling connector towards the second coupling connector.
Two problems associated with making up pressurized hydraulic couplings having poppet-type internal valving are overcoming the force required to unseat the poppet and overcoming the separating force in drawing the valve bodies together to fully open the poppets.
It is desirable to have a mechanical coupling having the advantages of a threaded connection that can be coupled easily and quickly. It is further desirable that the coupling is adapted for coupling while under pressure. It is also desirable that the coupling provide mechanical advantages to overcome the force required to unseat the poppet and overcome the separating force in drawing the valve bodies together to fully open the poppets.
The present invention is for a coupling mechanism having a receptacle assembly and a plug assembly. The plug assembly includes a latch body, coupling nut, inner body, and a first coupler connector. The latch body is secured to the coupling nut in such a manner as to permit the coupling nut to rotate relative to the latch body. The coupling nut threadably engages the inner body, making up the plug assembly. The inner body moves longitudinally as the coupling nut is rotated. The first coupler connector is connected to the inner body.
The receptacle assembly includes a receptacle shell and a second coupler connector. The receptacle shell is constructed to accept the latch body. The receptacle shell and latch body connection can be accomplished by a variety of latches or interlocking mechanisms. The latch body and the receptacle shell are securely engaged by rotating the coupling nut clockwise which causes the inner body of the plug assembly to translate forward thereby securely engaging the receptacle shell. The continued clockwise rotation of the coupling nut results in the completion of the coupling connection of the first coupler connector and the second coupler connector. The coupling connection of the first coupler connector and the second coupler connector is effectuated by a permanently threaded engagement of the coupler nut and the inner body which is within a sealed chamber.
Rotation of the coupling nut counter-clockwise causes the inner body to retract or translate rearwardly to firstly disengage the coupling connection and secondly, disengage the receptacle shell from the inner body.
The present invention includes a plurality of gear teeth on the coupling nut and a key hole or socket in the latch body. A key device interacts with the plurality of gear teeth and the key hole to provide the mechanical advantage to unseat the poppet and break the seal. Breaking the seal of the poppet requires a small amount of axial movement. Thus, a high torque is required for only a small rotation of the coupling nut. The mechanical advantage provided by the present invention overcomes the high required torque.
Once the poppet seal is broken, the separating forces created by the pressure acting on the area of the opposing faces of the plug and receptacle becomes unacceptable in terms of bearing and thread loading rendering the torque requirements to rotate the coupling nut untenable. Thus, the present invention provides a passageway communicating fluid pressure to a chamber formed by seal glands on the outside diameter of the receptacle and the bore diameter of the latch body. The annular area is sized to provide a slight biased force toward coupling which in essence negates or nullifies forces providing a zero resultant force.